Transport behavior of commercially available 100-Omega standard resistors

Several types of commercial 100-Omega resistors can be used with the cryoge nic current comparator to maintain the resistance unit, derived from the qu antized Hall effect (QHE), and to disseminate this unit to laboratory resis tance standards, Up until now, the transport behavior of these resistors ha s not been investigated. Such an investigation is of importance for carryin g out comparisons that are close to the level of a direct comparison of two QHE apparatuses, A set of five 100-Omega resistors from three different ma nufacturers has been sent to 11 participating national metrological institu tes. Ah laboratories but one have measured the resistors based on their lab oratory's quantized Hall resistance measurements. A constant drift model ha s been applied, and the results are evaluated in such a way that the transp ort properties of these resistors are treated independently for the differe nt types of resistor, Under certain conditions, these resistors allow compa risons with uncertainties better than 1 part in 10(8).